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C. E. JAQOT.

Watch. No. 20,491. Patented June 8,1858.

JMZL 2g 6% I UNITED STATES PATENT @FFTQE.

C. E. JACOB, OF NEW YORK, N. Y.

STOP-"WATCH.

Specification of Letters Patent No. 20,491, dated June 8, 1858.

To all whom it may concern:

Be it known that I, CHARLES E'JAcoB, of the city, county, and State of New York, have invented, made, and applied to use a certain new and useful Improvement in Watches Having Two Trains andlndependent Second-Hands; and I do hereby declare that the following is a full, clear, and exact description of the construction and operation of the same, reference being had to the annexed drawing, making part of this specification, wherein Figure l, is a plan of the ordinary wheel and whip for denoting quarter seconds, Fig. 2, is a plan, and Fig. 3, is a side view of my improved whip and connection to the balance.

Similar marks of reference denote the same parts.

My said invention applies to those watches that are used for marking accurately certain intervals of time, such as the speed of horses, railway trains, astronomical observations, &c., by means of two spring barrels and trains, the one train going to the balance, and keeping regular time in hours and minutes, and sometimes seconds; while the other train is connected With a hand denoting seconds, and another hand denoting quarter seconds or other integral parts, and this second train is provided with a stop motion by which the train is stopped at precisely the time desired, the main train and balance wheel continuing its rotation.

In order to show my improvement I have introduced the Fig. 1, showing an ordinary whip and its wheel for denoting quarter seconds.

The wheels and other parts are shown about three times the ordinary size for the purpose of better illustration in all the figures.

In Fig. 1, the wheel a, containing thirty teeth in the ordinary plan is riveted into the escapement wheel, a very delicate operation, and difficult to adjust. Z), is the whip or fly cross, set on the arbor 1, the pinion of which receives motion from the last wheel of the independent train and the wheels and pinions are so proportioned that this arbor 1, rotates once in each second as indicated by the independent second hand. The balance having four pulsations to the second and the anchor escapement allowing the escapement wheel to move each pulsation, one of the teeth of the wheel a, allows one arm of the whip b, to pass every quarter second. This requires great accuracy of workmanship and adjustment, and the whip moving in the same direction as the escapementwheel increases its power, and makes the watch move faster when the two trains are running together; and when the stop motion is applied the whip has to be moved to about the position shown by dotted lines, in order that the whip may not come in contact with the said wheel a, as it revolves with the escapement, thus neither the exact stopping nor starting point are apparent.

The nature of my said invention as distinguished from the foregoing consists in combining the whip or fly cross with the anchor escapement in such a manner that each vibration of said anchor escapement either one way or the other shall allow one arm of said whip to pass and thus indicate quarter or other integral parts of a second by a hand on the arbor of said fly.

In Figs. 2, and 3, (Z, is the plate of the watch. 0, is the balance wheel, 6, is the le ver, anchor or equivalent escapement actuated by any suitable escapement wheel, all these parts are in the usual form and act in the well known manner, the said escapement wheel f being driven by a train to the main spring barrel; 2' is the whip on the arbor 2, which is rotated by a train of wheels to the second spring box, and the said arbor 2, carries the quarter second hand 8, showing on the dial, see dotted lines.

In order to prevent any strain on the anchor escapement and cause an increase or decrease of power when the independent train is in action, I apply my whip at such a point that its power bears directly against the center (5) of the escapement, by acting on a pin or its equivalent (a) which for convenience I have here shown on an arm a, but said pin might be on the lever of the escapement itself. In order to pass one arm of the whip each vibration of the balance and escapement I form the ends of the whip alternately as shown in Figs. 4, and 5, so that when the anchor is in the position shown in Fig. 2, the part 6, will take against the pin 4, and when the pin 4 moves toward the cen ter of the whip the adjoining notch passes over the pin, and the end 7, of the next arm comes around against it, from which in its turn the pin 4, moves away, and the part 6 of the next arm comes around against said pin 4:.

When the watchs independent train is to be stopped the pin 8, is to be moved up by the lever 0, or its equivalent, which pin 8, taking the slightly beveled end of one of the arms on the whip slightly turns said whip back, just enough to prevent the pin 4 on the escapement rubbing on the arm of the whip; and the instant this pin 8, is moved back by the stop motion lever the whip com mences its rotation once a second and making as many pauses each rotation as there are vibrations to the balance.

From the foregoing it will be seen, that by this improvement I have made of taking the let off from the escapementitself instead of the escapement wheel, all the before mentioned difliculties in the old plan are avoided,

CHAS. E. JACOB. Vitnesses:

LEMUEL WV. SERRELL, THOMAS G. HAROLD. 

